During the 1996 ice jam flooding, the U.S. Army
decreases downstream discharge. Because of its
Corps of Engineers provided resources and tech-
heavy reliance on one data source, USGS records,
nical assistance to alleviate flood damage to
the database is spatially and temporally biased
affected communities. According to contemporary
toward ice events that occurred at USGS gaging
Corps Emergency Operations Situation Reports
stations during the period of USGS records. A third
(SITREPS), the Corps deployed more than 360,000
bias affecting the database is perception or stage-
sandbags to counties affected by ice jams in the
related; ice events with maximum stage less than
Buffalo, New York, area and the St. Paul District.
the perception stage may not be reported.
CRREL provided technical assistance in the form
Despite its biases, the database can be used to
of advice, referrals, and trips to visit ice jams in the
characterize ice events by region, to locate ice
New England Division (now District) and the fol-
event sites, and to identify a seasonal frequency
lowing districts: Buffalo, Chicago, Detroit, Kansas
distribution of ice events. Ice event frequency
City, New York, Omaha, Philadelphia, Sacra-
information can be used to guide a search of other
mento, Seattle, and Walla Walla. Specific examples
sources for material on unreported ice events. In
of the Corps and CRREL responses as described
addition, apparent trends in ice event data may
in the database are presented below.
shed light on their causes. Although ice event
In February 1996, an ice jam formed on the
damages are important, damage information is
Oswegatchie River, affecting the towns of Ant-
largely unavailable. As yet, statistical analyses of
werp and Oxbow, New York. The Corps assisted
reported damages have a high degree of uncer-
with the construction of a semi-permanent sand
tainty but may still provide useful information if
berm to reduce of flood threats (Lever 1996). An
the data biases are considered. The database is
engineer from CRREL visited the site at the
useful directly and indirectly in emergency
request of Buffalo District to assess the potential
response to ice events and can be used to guide
for short- and long-term ice-mitigation measures
detailed studies of ice problems and future
to reduce ice jam flooding in Oxbow.
research efforts. It is hoped that users of the
As noted previously, ice jams on the Susque-
CRREL Ice Jam Database will continue to provide
hanna River were severe and in particular caused
information on ice events not in the database, as
significant damage to the Safe Harbor Dam,
well as corrections to existing entries.
Conowingo Dam, and the town of Port Deposit in
Maryland. The Governors of Pennsylvania and
LITERATURE CITED
Maryland sought to improve forecasting and
warning for ice jams to reduce future damages. A
Berg, A. (1996) CENPS-CO-FL memorandum for
meeting of the Baltimore District, USGS, FEMA,
Chief, Emergency Management Branch. Flood
the Susquehanna River Basin Commission, and
fight report, Upper Clark Fork River Basin, 817
CRREL was held to discuss ice jam mitigation,
February 1996 (unpublished).
how to predict locations where ice jams are likely,
Bilello, M.A. (1961, 1964) Ice thickness observa-
and whether monitoring river conditions can help
tions, North American Arctic and Subarctic, 1958
to predict ice jams and improve warning time.
59 through 196162. USA Cold Regions Research
In the lower Lolo Creek area at Lolo, Montana,
and Engineering Laboratory, Special Report 43,
the Corps flood team provided technical assistance
Parts I, and II.
at several locations and participated in flood fight-
Bilello, M.A., and R.E. Bates (1966, 1969, 1971,
ing (Berg 1996). Corps involvement included sand-
1972, 1975, 1991) Ice thickness observations, North
bagging, construction of two diversion levees, con-
American Arctic and Subarctic, 196263 through
struction of temporary earth berms, plugging
197374. USA Cold Regions Research and Engi-
various irrigation ditches, removing ice, moving
neering Laboratory, Special Report 43, Parts III, IV,
an ice jam, and draining a flooded area (Berg 1996).
V, VI, VII and VIII.
The location of these operations included Drum-
Bilello, M.A., and V.J. Lunardini (1996) Ice thick-
mond, Clinton, and Lolo, Montana.
ness observations, North American Arctic and
Subarctic, 197475, 197576 and 197677. USA
Cold Regions Research and Engineering Labora-
SUMMARY AND CONCLUSIONS
tory, Special Report 43, Part IX.
The CRREL Ice Jam Database is a compilation
Breeding, R. (1996) Spring thaw comes early.
of data on a variety of known ice events, ranging
Missoulian [Missoula, Montana], 14 February.
from damaging ice jams to ice cover formation that
Campbell, L. (1983) Kuskokwim River ice jams
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